OTTAWA - It's just the thing conservative author, commentator and self-described polemicist Ann Coulter is known for: Dividing her audiences.

Coulter was scheduled to speak before an audience gathered at the University of Ottawa's Marion Hall Tuesday evening.

Instead, security concerns raised by the university kept the Republican firebrand from speaking.

Organizers pulled the plug on the speaking engagement because there were just too many people - too many of whom were just too rowdy.

"At a university, instead of free speech, censorship," said Ezra Levant, a Canadian conservative writer, lawyer and blogger who was scheduled to introduce Coulter.

Coulter was at the university for the second stop of her Canadian speaking tour to dish on political correctness, media bias and freedom of speech.

Police were called by the university to assist after students of all political stripes descended upon the auditorium to hear the talk - some of them lining up for more than two hours in the rain - only for it to be cancelled a half-hour after it was due to begin.

More than 2,000 people tried to get into the event, several times the capacity of the venue.

"We were called to ensure the crowd left in an orderly fashion," said Ottawa police Sgt. Rob Gilchrist. No arrests were made and no injuries were reported.

Hundreds of people pooled into the lobby in an attempt to get into the auditorium. Organizers, who turned away those who didn't register ahead of time, had allowed about 200 people into the auditorium when the fire alarm was pulled minutes before the talk was set to start.

The cancellation is regarded as a victory among those who showed up to protest the presence of Coulter, who is known for her inflammatory comments. She recently said Muslims shouldn't be allowed to travel in airplanes and should use flying carpets instead.

Groups gathered outside the building chanting "This is what free speech looks like" while the crowd inside could be heard chanting "We want Ann" after it was announced the event was cancelled at 8:15 p.m.

Organizers painted the cancellation as disgraceful.

"Francois Houle got his wish," Levant said of the University's provost and vice president. "He telegraphed to the community that University of Ottawa is not a place for free debate."

Houle had earlier sent Coulter a letter suggesting she brush up on the limits of free speech in Canada, adding that promoting hatred could lead to criminal charges. Coulter reacted angrily to the letter, saying Houle had threatened to charge her with a crime.

The university's student federation also vehemently opposed Coulter's appearance, banning posters advertising the talk from the University Centre building.

The event followed her Monday visit to London, Ont. where little of her speech touched on Canadian issues. Instead, she verbally attacked gay rights activists, the mainstream media and the Barack Obama administration.

Her Canadian tour will wrap up at the University of Calgary on Thursday.